Afterlife Game pack idea

I think it could be something in between of hunger and sleep needs, it decays when ghost is materializing meaning pretty much not being "asleep" in his grave and could be recharged either by "sleeping" in their gravestone/urn or by haunting living sims (could work like vampire drinking plasma with leaving sims exhausted with option of intensity). There could be new ectoplasm fruit or some new collectibles one of which could be ectoplasm. those could be collected by sims with spiritual skill mentioned before.

maybe it could decay more rapidly if the ghost is near or experiences their death cause like if died from laughter, near playful sims and looking at playful paintings. Or this could be solved as 3rd need "fear" or something like that it would drain only in proximity of death cause. If the bar expires it wouldn't kill the ghost but banish him for 24 hrs (maybe less) from material world. It should recharge pretty fast passively when ghost isn't close to death cause.
Don't really know what ghosts of sims that died of old age would be afraid of. Afraid of elders would be too extreme I think since it might be hard to take them away from "fear" factor.

But I imagine it would be hard to make and control.